Originally Posted by DoodleMan
My question now is, if my vet only wrote a 6 month prescription, do i need to go to the vet every 6 months to get a refill prescription and a heartworm test? If I have a year supply for my other dog, do I need to get him retested after 1 year or will vets generally refill the rx without another heartworm test?
WOW, I didn't know we both lived in Arizona!
If your vet wrote a script for only 6 months without refills, then yes you would have to go back for another script. I do not know if they would ask for another heartworm test, I would doubt it. The American Heartworm Society recommends it only yearly.
Heartworm disease is thought to be increasing in Arizona so many vets (including us) require yearly testing. While the HeartGard is 99.9% effective at preventing heartworm, birth control is also of a similar efficacy and there are still problems in that area. For this reason and the fact that if a pet does have heartworm disease, there can be little to no signs for an extended period of time while sometimes irreversible heart and lung damage is being created - yearly heartworm testing is recommended and often required. Usually the test is fairly inexpensive and takes only a few minutes to run. (our test is 3 blood drops and 10 minutes and has fantastic accuracy).
Why is heartworm disease increasing? There was a study done in California that showed that heartworm disease was identified in the wild coyote population from all aspects of the state. There is a thought that the wild animal reservoir is increasing in many states.